Method for producing a moulded rubber seal

ABSTRACT

A method is provided for producing centering elements in a molded rubber seal that is reinforced with metal. Metal is cut out of at least one edge area of the metal element and the freed material is shaped by being bent upwards away from the plane of the metal element. Elastomer material is then molded around the bent material above the cavity created by the shaping process, in order to produce a pre-definable final contour.

The invention concerns a procedure for producing centering agents in thefield of metallically strengthened molded rubber gaskets.

The utility model DE 20105250 UI illustrates a flat gasket with clampplates to its fixing on a sealing surface. It is a metallic flat gasgasket in which no Elastomer material is formed and not a molded rubbergasket.

A housing cover for crankshaft cases is taken from DE 4134316. Axialnoses are provided in the screw thread gears, which serve for centeringand can be molded with Elastomer material. A connection between theElastomer sealing lips and the Elastomer material is not provided, sothat the noses must be produced in a separate working cycle. Thishousing cover has nothing in common with a molded rubber gasket.

Molded rubber gaskets are used for example in the field area of internalcombustion engine valve caps or similar sealing casing parts. However,these molded rubber gaskets, which are to some extent relativelyunstable in their form, must be assembled in the sealing area. Here,assembly aids such as pressed-in or riveted metal pegs or molded plasticor rather Elastomer contours are used as centering agents. The economicefficiency of the previously produced molded rubber gaskets isunfavorably influenced by these additional metal pegs.

In the application of molded plastic or Elastomer contours, negativeinfluences are possibly recorded with regard to an Elastomer or materialshrinkage.

A housing cover is taken from DE-C 4 134 316, with several distributedscrew thread holes in a radial flange surface of the cover arranged onthe circulation as well as agents for a location-suitable fixing andcentering of the cover opposite the crankshaft case. The centeringagents are formed by at least two axial extending noses in the directionof the crankshaft case, which are bound in one clump with the radialflange surface. The noses are in corresponding drill-holes insertablewith the screw thread holes. On the outer circulation of the noses, anelastic layer can be arranged, which is integrally molded in a separateworking cycle on the housing cover.

A sealing has become known through the DE-C 4 223 486 with an insertthat is enclosed by Elastomer material, in which the insert featuresholes for taking in screws and, in the area of the holes, grout limitersformed out of the insert are provided. The latter are formed by thefolding-over of hole borders, so that in the hole area a double coatingthickness of the insert is produced.

The basis of the task for the invention is to provide a procedure forthe production of centering agents in the field of metallicallystrengthened molded rubber gaskets which involve a high positioningaccuracy of molded rubber gaskets. In addition, a metallicallystrengthened molded rubber gasket is to be planned which can easily bemade and safely used for positioning in the sealing area.

This task is solved in accordance with the invention by thecharacteristics of patent claim 1. Further advantageous formations ofthe procedure according to the invention are taken from the accompanyingclaims below.

Compared to the general state of technology, therefore, a possibility isshown to produce integral centering agents in the field of molded rubbergaskets. An economical solution is presented by these measures thatcontain no additional components (metal pegs or the like) and involve avery high positioning accuracy of the peg molded with Elastomermaterial.

Negative influences of the Elastomer shrinkage can be markedly reduced.According to demands on the centering, a strengthening of the Elastomergeometry can be realized, in which even greater heights of the centeringpeg are conceivable.

The object of invention is presented on the basis of an explanatoryexample in the drawing and is described as follows. It shows:

FIG. 1 Partial view of a metallic element with a free cut and materialformed out of it;

FIG. 2 Partial view according to FIG. 1 with molded rubber gasket;

FIG. 3 Cross-section through the metallic element in the area of themolded material formed with Elastomer material.

FIG. 1 shows as a partial view a metallic element 1, in whose borderarea 2 a free cut 3 predetermined contour was brought in. The free cutmaterial 4 is bent out under formation of a somewhat peg-like contourfrom level 5 of the metallic element 1 by essentially 90°, so that afree space 6 is produced, which forms a molding canal.

The metallic element is represented in FIG. 2, on which the moldedrubber gasket 7 is now molded. Above the free space 6, Elastomermaterial in the direction of the somewhat peg-like formed material 4 wasled in the same working cycle, in which the material 4 was molded fromElastomer material 8. The peg 4, originally provided with amulti-angular cross section, exhibits a somewhat circular contour in thecross section after its molding with Elastomer material 8.

FIG. 3 shows a cross section through the peg-like material 4 in thejoint on its jacket with the Elastomer material 8. It is noticeable thatthe material 4 is formed by about 90° from level 5 of the metallicelement 1. The given Elastomer material in the free space 6 (mold canal)is defined with the reference sign 9.

1. Procedure for the production of centering agents in the field of metallically strengthened rubber mold gaskets, in which in a border area of a metal element at least one free cut is made and material of the metal element bent out of a plane of the metal element to create a free space; introducting elastomer material into the free space and around the outwardly bent material during the formation of elastomeric sealing features of the gasket.
 2. Procedure according to claim 1, wherein the material is bent 90° from the plane of the metal element.
 3. Procedure according to claim 1, wherein the bent material is formed with polygonal cross section of the metal element and afterwards molded to a substantially circular cross section with elastomer material. 